preloader hooks

code/controllers/subsystem/atoms.dm

@@ -137,7 +137,30 @@ SUBSYSTEM_DEF(atoms)
 /datum/controller/subsystem/atoms/proc/instance_atom_immediate(path, mapload, atom/where, ...)
 	var/old_init_status = atom_init_status
 	atom_init_status = mapload? ATOM_INIT_IN_NEW_MAPLOAD : ATOM_INIT_IN_NEW_REGULAR
-	var/atom/created = new path(arglist(args.Copy()))
+	var/atom/created = new path(arglist(args.Copy(3)))
+	atom_init_status = old_init_status
+	return created
+
+/**
+ * immediately creates and inits an atom with a preloader callback.
+ *
+ * @params
+ * * path - typepath
+ * * mapload - treat as mapload?
+ * * preload_call - callback to invoke with (created) for the created atom. This is not allowed to sleep.
+ * * where - location to init at
+ * * ... - rest of args are passed to new() / Initialize().
+ */
+/datum/controller/subsystem/atoms/proc/instance_atom_immediate_with_preloader(path, mapload, datum/callback/preload_call, atom/where, ...)
+	var/old_init_status = atom_init_status
+	atom_init_status = ATOM_INIT_IN_SUBSYSTEM
+	var/atom/created = new path(arglist(args.Copy(4)))
+	preload_call.invoke_no_sleep(created)
+	atom_init_status = mapload? ATOM_INIT_IN_NEW_MAPLOAD : ATOM_INIT_IN_NEW_REGULAR
+	// this sets 'where' to if we should be mapload.
+	// this is acceptable because args[4] ('where') is not used again.
+	args[4] = mapload
+	InitAtom(created, FALSE, args)
 	atom_init_status = old_init_status
 	return created
 

code/datums/recipe/stack_recipe.dm

@@ -52,13 +52,30 @@
 	var/on_border = FALSE
 	// todo: material constraints
 
+	//* Product Descriptors *//
+
+	/// Automatically create empty storage / cells / containers / whatever
+	/// * Usually this is on, because usually stacks are not meant to create the insides of a container.
+	var/product_auto_create_empty = TRUE
+
+	//* Internal *//
+
+	/// preloader callback, do not touch
+	var/datum/callback/preloader_callback
+
 /datum/stack_recipe/New()
 	if(ispath(result_type, /obj/item/stack))
 		result_is_stack = TRUE
 
 	var/atom/casted = result_type
 	on_border = !!(initial(casted.atom_flags) & ATOM_BORDER)
 
+	preloader_callback = CALLBACK(src, make_preload_hook)
+
+/datum/stack_recipe/Destroy()
+	QDEL_NULL(preloader_callback)
+	return ..()
+
 /**
  * attepmt to craft
  *
@@ -131,6 +148,7 @@
  * * creating - (optional) list will be populated of objects created. supply a list so you can read it, or don't to ignore.
  */
 /datum/stack_recipe/proc/make(atom/where, amount, obj/item/stack/stack, mob/user, silent, use_dir, list/created = list())
+	#warn preload call for making sure stacks get made empty
 	if(result_is_stack)
 		var/obj/item/stack/casted = result_type
 		var/max_amount = initial(casted.max_amount)
@@ -139,16 +157,22 @@
 			if(!--safety)
 				CRASH("safety hit")
 			var/making_amount = min(amount, max_amount)
-			var/obj/item/stack/creating = new result_type(where, making_amount)
+			var/obj/item/stack/creating = Ssatoms.instance_atom_immediate_with_preloader(result_type, FALSE, preloader_callback, where, making_amount)
 			amount -= making_amount
 			created += creating
 	else
 		for(var/i in 1 to min(amount, 50))
-			var/atom/movable/creating = new result_type(where)
+			var/atom/movable/creating = Ssatoms.instance_atom_immediate_with_preloader(result_type, FALSE, preloader_callback, where)
 			creating.setDir(use_dir)
 			created += creating
 	return TRUE
 
+/**
+ * preloads an atom we make
+ */
+/datum/stack_recipe/proc/make_preload_hook(atom/product)
+	product.preload_from_stack_recipe(src)
+
 /**
  * tgui stack recipe data
  */

code/game/atoms/_atom.dm

@@ -234,13 +234,17 @@
 
 /**
  * Called by the maploader if a dmm_context is set
+ *
+ * todo: rename to preload_from_mapload()
  */
 /atom/proc/preloading_instance(datum/dmm_context/context)
 	return
 
 /**
  * hook for abstract direction sets from the maploader
  *
+ * todo: this might need to be part of preloading_instance; investigate
+ *
  * return FALSE to override maploader automatic rotation
  */
 /atom/proc/preloading_dir(datum/dmm_context/context)

code/game/objects/items/storage/storage.dm

@@ -42,14 +42,15 @@
 	var/storage_datum_path = /datum/object_system/storage
 	/// Cleared after Initialize().
 	/// List of types associated to amounts.
+	//  todo: stack handling
 	var/list/starts_with
 	/// set to prevent us from spawning starts_with
 	var/empty = FALSE
 
 /obj/item/storage/Initialize(mapload, empty)
 	. = ..()
 	initialize_storage()
-	if(!empty)
+	if(!empty || src.empty)
 		spawn_contents()
 		legacy_spawn_contents()
 	else
@@ -59,7 +60,7 @@
  * Make sure to set [worth_dynamic] to TRUE if this does more than spawning what's in starts_with.
  */
 /obj/item/storage/proc/spawn_contents()
-	if(length(starts_with) && !empty)
+	if(length(starts_with))
 		// this is way too permissive already
 		var/safety = 256
 		var/atom/where_real_contents = obj_storage.real_contents_loc()